1. Field of the Invention
The present invention relates to a front suspension structure of a motorcycle, more particularly to a front suspension structure having a shock absorber and a front fork provided as separate components.
2. Background Art
Japanese Patent Laid-open No. Sho. 59-20784 discloses a motorcycle link-type front suspension structure of the related art having a shock absorber that is not assembled inside a front fork, but is instead arranged separately and independently from a front fork. The disclosed front suspension structure has a swing arm (axle support arm) provided so as to bridge between a lower end of a front fork and an axle, a lower end of a cushion arm linked to the middle of the swing arm, an upper end of the cushion arm linked to a lower end of the shock absorber, and an upper end of the shock absorber linked to a top bridge.
With these types of front suspension structures, vibration of the swing arm during travel is conveyed to the shock absorber through the cushion arm, and a specified buffering action is exhibited. The lower end of the cushion arm is directly attached to the front fork in the above-described technique of the related art. Also, the upper end of the cushion arm is attached to the front fork via a tension rod.
However, the front fork and the cushion arm are manufactured separately, and it is inevitable that a distance between left and right fork pipes will vary as each manufactured component will exhibit varying design values. Accordingly, the extent to which left and right fork pipes constituting the front fork are parallel, and the position of the top bridge and a bottom bridge etc. will be slightly different as the actual manufactured values for each manufactured component will vary from desired design parameters.
The method of attaching the cushion arm of this type of conventional structure to a front fork involves fixing a bracket to the front fork and linking the cushion arm to this bracket at specified locations. Unfortunately, the distance and degree of parallelism between the fork pipes is slightly different for each manufactured component, thereby making it difficult to obtain lateral positional precision and parallel positional precision for the installation and positioning of the cushion arm.
The present invention overcomes the shortcomings associated with the related art and achieves other advantages not realized by the related art.
An object of the present invention is to improve the installation of cushion arms in front suspension structures by improving the lateral positioning precision and parallel precision of installed components.
A further object of the present invention is to provide a front suspension structure that offers simple and reliable positional adjustment of front suspension components, including stays and cushion arms.
A further object of the present invention is to reduce friction as a result of shock absorbing motion being conveyed between components of a front suspension structure.
These and other objects are accomplished by a front suspension structure comprising a front fork having right and left fork pipes, a cushion arm attachment stay attached to each of the right and left fork pipes, a cushion arm for oscillating in response to a vertical motion transmitted from the front fork, a top bridge and a bottom bridge, and a shock absorber, wherein the front fork and the shock absorber are separate components with an upper end of the shock absorber linked to a top bridge side, and a lower end of the shock absorber linked to the cushion arm, the cushion arm swingably supported between the cushion arm attachment stays via a shaft.
These and other objects are accomplished by a front suspension support structure connected to a steering system of a motorcycle, the front suspension structure comprising a top bridge attached to an upper end of the steering system, a bottom bridge attached to a lower end of the steering system, an upper part of a front fork supported by the top bridge and the bottom bridge, and a lower end of the front fork is connected to an arm holder, a first end of an axle support arm is swingably attached to an axle of a front wheel of the motorcycle, cushion arm attachment stays attached to the front fork, and a cushion arm, swingably supported between the cushion arm attachment stays and linking a lower end of a shock absorber via a shaft.
In order to make it possible to positionally adjust the stays attached to each of the left and right fork pipes in an axial direction of the fork pipes and around the fork pipes, the attachment position and attachment direction of the stay relative to the cushion arm is adjusted, and the lateral positioning precision and parallel precision can be improved. According to a preferred embodiment of the present invention, positional adjustment can be accomplished through the simple adjustment of a few securing bolts.
Furthermore, by using a divided structure for the cushion arm attachment stays, positional adjustment can be carried out easily.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are give by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.